Rather than having drivers jump cars and see top drivers in bad cars and midfield drivers in top cars, it would be better to have all drivers in similar cars. That way we could really see which drivers are making the difference. The idea of drivers jumping cars, though interesting, is probably not realistic.
I'd be for maybe having two one hour races, as, the way it is now, starts and finishes are the better parts of races. Might as well have two of each. Could be one race in each direction.
Not that wacky, has been tried before, should be tried again: one set of tyres per race.
Unlimited number of blocking moves per straight.